In an electric power system, overcurrent (OC) or excess current is a situation where a larger than intended electric current exists through a conductor, leading to excessive generation of heat, and the risk of fire or damage to the equipment and system failure. Possible causes for overcurrent include short circuits, excessive load, and incorrect design. Fuses, circuit breakers, temperature sensors and current limiters are commonly used protection mechanism to control the risks of overcurrent.
With the advance of semiconductor technologies and the like, the performance of Central Processing Units (CPUs) and processors used in electronic devices has been improved remarkably. For example, an operating frequency of the level of GHz has been used widely in mobile phones. When the system speed and core requirements reach higher limits, the power consumption of CPUs and processors is also increasing. Power management integrated circuits (PMICs) are integrated circuits for managing power requirements of the host system. A PMIC is often included in battery-operated devices such as mobile phones and portable media players.
When the PMIC of the host system is over loaded and the CPU activity is high, it indicates that the CPU may be facing excessive power consumption and overcurrent situation. A fast and autonomous solution for providing CPU over-current protection is sought.